patch 7.4.2244
Problem:    Adding pattern to ":oldfiles" is not a generic solution.
Solution:   Add the ":filter /pat/ cmd" command modifier.  Only works for some
            commands right now.
diff --git a/src/proto/message.pro b/src/proto/message.pro
index ba8ff37..7112b09 100644
--- a/src/proto/message.pro
+++ b/src/proto/message.pro
@@ -43,6 +43,7 @@
 void msg_puts_long_attr(char_u *longstr, int attr);
 void msg_puts_long_len_attr(char_u *longstr, int len, int attr);
 void msg_puts_attr(char_u *s, int attr);
+int message_filtered(char_u *msg);
 void may_clear_sb_text(void);
 void clear_sb_text(void);
 void show_sb_text(void);